Adjustable die.



P. W. STREGKER.

ADJUSTABLE DIE. APPLICATION FILED AUG. 25, 1913.

1,087,073.' Patented Feb. 10, 1914 UEE STATES PATEN nic FREDERICK W. STRECKER, OF GREENFIELD, MASSACHUSETTS, ASSIGNOR TO GREEN- FIELD TAP @c DIE CORPORATION, OF GREENFIELD, MASSACHUSETTS, A CORPORA- TION 0F MASSACHUSETTS.

ADJUSTABLE '.DIE.

Specification of Letters Patent.

Patented Feb. 10, 1914.

Application led August 25, 1913. Serial No. 786,497.

To all whom it may concern Be it known that I, FREDERICK W. STECKER, a citizen of the United States of America, residing at Greenfield, in the county of Franklin and State of Massachusetts, have invented certain new and useful Improvements in Adjustable Dies, of which the following is a specification.

Thisv invention relates to improvements in adjustable die plates or holders. Heretofore, in this class of inventions, the two members which compose the parts of the die are constantly becoming separated from each other. This separation occurs, when the screw element which serves to retain the members of the die in place on the base-member becomes loose or worn.

The object of the present invention is, therefore, to provide suitable means to permit the usual close adjustment of the members of the die, and, at the same time retain or prevent these members from becoming separated from each other a comparatively wide distance apart.

The invention, in general, comprises a basemember which serves as a guide for the piece of work and to which the two members which compose the thread-forming die are secured. These members are pivotally connected at one end to the base-member by suitable means, and, between their opposite ends is located an adjusting device formed with a tapered surface.

Referring to the drawings, which form a part of the specification, Figure 1 is a plan view of the completed die, showing in full lines the closed position of the threadforming members, and, in dotted lines their open position. Fig. 2 1s an edge elevational view of the die indicating in dotted lines the retaining device to prevent the separation of the device located therein. Fig. 3 is a vertical sectional view on the'line 3-3 of Fig. 1, showing the improvement in detail. Fig. 4 is a vertical sectional view on the line 4-4 of Fig. 1, showing the hinge element about which the thread-forming members are pivoted and Figs. 5 and 6 are detail views of the split ring.

Referring to the drawings in detail, 1 designates the usual base-piece or member to which the thread-forming members 2 and 3 are secured, the cutting teeth being indicated at 4 and 5.

6 indicates a pivot about which the members 2 and 3 move, and which is formed with a thread 7, at its lower end that is re-y cling the tapered port-ion 9 of the adjusting.y

screw 8 is a split sleeve or band element 11, formed from elastic or tempered material. This element is located in the semi-circular recessed portions 12 and 13 of the members 2 and 3, as indicated clearly in Fig. 3. The

split in the sleeve isindicated at 14. The upper edge-portion of the sleeve is slightly tapered as indicated at 15, to engage the.

tapered-portion of the screw 8.

The operation of the adjusting device is as follows: The pivot screw 6 is tightened a sufficient amount to permit the members 2 and 3 to move or turn on the same without too much friction. If it is desired to adjust the diametrical distance between the threads 4 and 5, the screw 8 is turned either inwardly or outwardly. This operation causes the split sleeve 11 to expand and open or separate the members 2 and 3. If the screw 8 is turned outwardly allowing members 2 and 3 to come together in the holder, the sleeve 11 contracts correspondingly, since the lower edge of the split ring 1l, it will be observed, is located in the grooves 16 in the two members 2 and 3, these grooves being formed by the rib 17 on each of the members 2 and 3. Even if the adjusting screw 8 is left in a position and exerting little or no pressure on the split ring or sleeve 11, the members 2 and 3 will be retained and prevented from becoming widely separated. If the ring was not used, however, andthe pivot screw 6 is fairly loose there would be nothing to prevent the members 2 and 3 from swinging widely apart if the adjusting screw 8 is loosened and left in that position. The split ring or sleeve 11, therefore, serves to always retain the members in place, and, at the same time permits these members to be carefully adjusted by means of the screw 8.

What I claim is 1. In a die construction, the combination with the base-plate and thread forming members thereof, a pivot screw to retain the members in place on the base-plate and to permit them to move for adjustment purposes, an adjusting screw formed with a tapered upper portion to engage recesses in the adjacent edges of said members-the upper portions ot' the recesses beingL formed with a groove in each member, a split ring located in the grooves and encircling` the tapered upper portion et the adjustingl screw, whereby the thread liorming` members are prevented from becoming separated, as described.

2. An adjustable die Construction comprising a base-plate and threacl-forming` members pivotaily secured thereto, means to adjust said members toward and from each other, and means, engaging the adjust-ing means, to prevent said members from be coming` separated.

A thread-forming device, comprising in combination a base-plate member, a pair of thread forming members pivotally secured at one oi' their ends to said member, the opposite ends of said members having their adjacent edges recessed, a taper-shaped adjusting member attached to the base-plate member and entering the recessed portions, the recessed portions each having a groove therein, and a split sleeve engaging the grooves and encircling the taper-shaped adjnsting member, as described.

FREDERCK W. STRECKER.

lVitnesses H. C. ROBINSON, FREDK. H. PAYNE.

opies of this patent may be obtained for five cents each, by addressing the Commissioner of Eatent,

. Washington, D. C. 

